Efficacy of Cloxacillin and Fosfomycin Combination Versus Cloxacillin Monotherapy in Patients With MSSA Bacteremia

Summary

Background: Despite management improvement in lasts years, S.aureus bacteremia leads to high morbidity and mortality. For over 50 years, methicillin-susceptible S.aureus (MSSA) bacteremia standard treatment was cloxacillin. Previous studies using different therapies and combination treatment fall to improve survival in these patients. Aim: to demonstrate the efficacy of the cloxacillin and fosfomycin combination administered during the first week of treatment, compared with cloxacillin monotherapy in patients with MSSA bacteremia in treatment success. Methods: A multicentre, superiority, open-label, randomized, phase IV-III, two-armed parallel (1:1) groups clinical trial. Adult patients with MSSA bacteremia will be randomized to Combination therapy group: patients will receive intravenous cloxacillin 2g/4h and fosfomycin 3 g/6h for the duration of 7 days treatment, or Standard therapy group: patients will receive intravenous cloxacillin 2g/4h for the duration of 7 days IV treatment. After the first week, antibiotic treatment and duration will be decided by responsible clinician following clinical practice. The primary endpoint is the treatment success measured at day 7 of treatment; a composite endpoint defined by all of the following criteria met after randomization: patient alive at day 7 AND stable or improved quick SOFA score (compared with baseline) at day 7 AND fever resolved at day 7 AND negative blood cultures for S. aureus at day 7. In case of achieving statistical differences in the primary endpoint, investigators will perform a hierarchical analysis of the treatment success at Test of Cure visit (TOC, 12 weeks after randomization), defined by the presence of all of the following: patient alive at TOC AND no evidence of microbiological treatment failure defined as isolation of S. aureus from blood culture or other sterile site from day 8 after randomization until TOC. Investigators have assumed a 74% of treatment success in monotherapy group. Accepting an alpha risk of 0.05 and a beta risk of 0.2 in a two-sided test, 183 subjects are necessary in first group and 183 in the second to find a statistically significant difference of 12%. It has been anticipated a drop-out rate of 5%. Discussion: Randomized studies assessing efficacy of different treatment in MSSA bacteremia are lacking. This study could help to improve knowledge about MSSA bacteremia and whether combined treatment with cloxacillin and fosfomycin could improve outcomes compared with standard treatment.

Timeline

Start

2019-05-31

Primary completion

2022-02-24

Completion

2022-02-24

Publications

• Background Bergin SP, Holland TL, Fowler VG Jr, Tong SYC. Bacteremia, Sepsis, and Infective Endocarditis Associated with Staphylococcus aureus. Curr Top Microbiol Immunol. 2017;409:263-296. doi: 10.1007/82_2015_5001.
• Background van Hal SJ, Jensen SO, Vaska VL, Espedido BA, Paterson DL, Gosbell IB. Predictors of mortality in Staphylococcus aureus Bacteremia. Clin Microbiol Rev. 2012 Apr;25(2):362-86. doi: 10.1128/CMR.05022-11.
• Background Gasch O, Camoez M, Dominguez MA, Padilla B, Pintado V, Almirante B, Molina J, Lopez-Medrano F, Ruiz E, Martinez JA, Bereciartua E, Rodriguez-Lopez F, Fernandez-Mazarrasa C, Goenaga MA, Benito N, Rodriguez-Bano J, Espejo E, Pujol M; REIPI/GEIH Study Groups. Predictive factors for mortality in patients with methicillin-resistant Staphylococcus aureus bloodstream infection: impact on outcome of host, microorganism and therapy. Clin Microbiol Infect. 2013 Nov;19(11):1049-57. doi: 10.1111/1469-0691.12108. Epub 2013 Jan 17.
• Background Minejima E, Mai N, Bui N, Mert M, Mack WJ, She RC, Nieberg P, Spellberg B, Wong-Beringer A. Defining the Breakpoint Duration of Staphylococcus aureus Bacteremia Predictive of Poor Outcomes. Clin Infect Dis. 2020 Feb 3;70(4):566-573. doi: 10.1093/cid/ciz257.
• Background Gudiol F, Aguado JM, Almirante B, Bouza E, Cercenado E, Dominguez MA, Gasch O, Lora-Tamayo J, Miro JM, Palomar M, Pascual A, Pericas JM, Pujol M, Rodriguez-Bano J, Shaw E, Soriano A, Valles J. Diagnosis and treatment of bacteremia and endocarditis due to Staphylococcus aureus. A clinical guideline from the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC). Enferm Infecc Microbiol Clin. 2015 Nov;33(9):625.e1-625.e23. doi: 10.1016/j.eimc.2015.03.015. Epub 2015 May 1.
• Background Thwaites GE, Scarborough M, Szubert A, Nsutebu E, Tilley R, Greig J, Wyllie SA, Wilson P, Auckland C, Cairns J, Ward D, Lal P, Guleri A, Jenkins N, Sutton J, Wiselka M, Armando GR, Graham C, Chadwick PR, Barlow G, Gordon NC, Young B, Meisner S, McWhinney P, Price DA, Harvey D, Nayar D, Jeyaratnam D, Planche T, Minton J, Hudson F, Hopkins S, Williams J, Torok ME, Llewelyn MJ, Edgeworth JD, Walker AS; United Kingdom Clinical Infection Research Group (UKCIRG). Adjunctive rifampicin for Staphylococcus aureus bacteraemia (ARREST): a multicentre, randomised, double-blind, placebo-controlled trial. Lancet. 2018 Feb 17;391(10121):668-678. doi: 10.1016/S0140-6736(17)32456-X. Epub 2017 Dec 14.
• Background Grillo S, Cuervo G, Carratala J, Grau I, Pallares N, Tebe C, Guillem Tio L, Murillo O, Ardanuy C, Dominguez MA, Shaw E, Gudiol C, Pujol M. Impact of beta-Lactam and Daptomycin Combination Therapy on Clinical Outcomes in Methicillin-susceptible Staphylococcus aureus Bacteremia: A Propensity Score-matched Analysis. Clin Infect Dis. 2019 Oct 15;69(9):1480-1488. doi: 10.1093/cid/ciz018.
• Background Grabein B, Graninger W, Rodriguez Bano J, Dinh A, Liesenfeld DB. Intravenous fosfomycin-back to the future. Systematic review and meta-analysis of the clinical literature. Clin Microbiol Infect. 2017 Jun;23(6):363-372. doi: 10.1016/j.cmi.2016.12.005. Epub 2016 Dec 9.
• Background Chan AW, Tetzlaff JM, Altman DG, Laupacis A, Gotzsche PC, Krleza-Jeric K, Hrobjartsson A, Mann H, Dickersin K, Berlin JA, Dore CJ, Parulekar WR, Summerskill WS, Groves T, Schulz KF, Sox HC, Rockhold FW, Rennie D, Moher D. SPIRIT 2013 statement: defining standard protocol items for clinical trials. Ann Intern Med. 2013 Feb 5;158(3):200-7. doi: 10.7326/0003-4819-158-3-201302050-00583.
• Grillo S, Pujol M, Miro JM, Lopez-Contreras J, Euba G, Gasch O, Boix-Palop L, Garcia-Pais MJ, Perez-Rodriguez MT, Gomez-Zorrilla S, Oriol I, Lopez-Cortes LE, Pedro-Botet ML, San-Juan R, Aguado JM, Gioia F, Iftimie S, Morata L, Jover-Saenz A, Garcia-Pardo G, Loeches B, Izquierdo-Cardenas A, Goikoetxea AJ, Gomila-Grange A, Dietl B, Berbel D, Videla S, Hereu P, Padulles A, Pallares N, Tebe C, Cuervo G, Carratala J; SAFO study group. Cloxacillin plus fosfomycin versus cloxacillin alone for methicillin-susceptible Staphylococcus aureus bacteremia: a randomized trial. Nat Med. 2023 Oct;29(10):2518-2525. doi: 10.1038/s41591-023-02569-0. Epub 2023 Oct 2.
• Grillo S, Cuervo G, Carratala J, San-Juan R, Aguado JM, Morata L, Gomez-Zorrilla S, Lopez-Contreras J, Gasch O, Gomila-Grange A, Iftimie S, Garcia-Pardo G, Calbo E, Boix-Palop L, Oriol I, Jover-Saenz A, Lopez-Cortes LE, Euba G, Aguirregabiria M, Garcia-Pais MJ, Gioia F, Pano JR, Pedro-Botet ML, Benitez RM, Perez-Rodriguez MT, Meije Y, Loeches-Yague MB, Horna G, Berbel D, Dominguez MA, Padulles A, Cobo S, Hereu P, Videla S, Tebe C, Pallares N, Miro JM, Pujol M; SAFO study group and the Spanish Network for Research in Infectious Diseases (REIPI). Multicentre, randomised, open-label, phase IV-III study to evaluate the efficacy of cloxacillin plus fosfomycin versus cloxacillin alone in adult patients with methicillin-susceptible Staphylococcus aureus bacteraemia: study protocol for the SAFO trial. BMJ Open. 2021 Aug 5;11(8):e051208. doi: 10.1136/bmjopen-2021-051208.

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